DESCRIPTION: Recent macroeconomic modeling suggests that health has a substantial impact on the growth of per capita GDP (Gross Domestic Product) and is, thus, a critical input to economic development. The macroeconomic mechanisms by which a healthier population contributes to a country's economic growth, however, are poorly understood. One important pathway about which we know little is the impact of adult morbidity on labor productivity. The specific aim of the proposed study is to assess the impact of major acute and chronic adult morbidities on agricultural labor productivity in rural sub-Saharan Africa. It will answer two key research questions: 1) What is the impact of malaria, HIV/AIDS, and tuberculosis on individual labor productivity? and 2) To what extent does adult morbidity hinder economic development through its impact on wages and profits? The study will also create opportunities to strengthen local capacity to conduct interdisciplinary research on the relationship between health and development. The study will use retrospective and prospective data from a group of large agricultural estates in western Kenya, including individual daily output (weight of crop harvested per day) records and detailed morbidity data. By linking these two data sets, the study will be able to observe directly both productivity and health, overcoming a major limitation of most previous research. The data set is expected to include approximately 870 cases of malaria, 420 cases of HIV, and 430 cases of tuberculosis; each case will have an average of 270 daily productivity observations per year. These data will allow the study to determine the effect of morbidity on three aspects of productivity: reduced performance on the job, absenteeism, and the loss of workforce experience when a sick worker leaves the workforce prematurely. Productivity losses will be assessed from the date of infection to full recovery or departure from the workforce. The study will also measure the effects of concurrent infections with HIV and malaria or HIV and TB and will describe the relationship between biomedical indicators of disease (CD4 [a member of the immunoglobulin superfamily] counts, malaria parasite densities, and lib levels) and labor productivity. The results of the productivity analysis will be used to estimate the impact of adult morbidity on wage income and firm profits, two of the most important components of gross domestic product. The study will also estimate the extent to which labor substitution offsets the impacts on wages and profits. The study is distinguished by the opportunity to link a large amount of individual productivity data to a medical records system with good diagnostic capabilities, which will allow it to generate empirically robust estimates of the impact of common adult morbidities at the macroeconomic level. The study will help explain whether and how the impacts of adult morbidity on wages and profits can generate the macroeconomic effects reported in recent cross-country analyses. It will thus help to fill a critical gap in our knowledge about the relationship between health and economic development.